CM850 Electronic Control System – FAULT CODE 319

Real-Time Clock Power Interrupt – Data Erratic, Intermittent or Incorrect


Fault Code: 319
PID: P251
SPN: 251
FMI: 2/2
LAMP: Amber (Maintenance Flashout)

Real-Time Clock Power Interrupt – Data Erratic, Intermittent or Incorrect. Real-time clock lost power.

None on performance. Data in the ECM will not have accurate time and date information.

Real-Time Clock Power Circuit

Circuit Description

Under ordinary operating conditions, the real-time clock in the electronic control module (ECM) is powered by the vehicle’s batteries. If battery power to the ECM is lost, then the real-time clock will be powered by a battery in the engine harness (if equipped).

Component Location

The real-time clock battery is secured to the engine harness near the ECM. Refer to Procedure 100-002 (Engine Diagrams) in Section E for a detailed component location view.

Shop Talk

This fault indicates that the real-time clock in the ECM lost power. Possible causes for this fault are weak or failed real-time clock battery, failed wiring or connectors between the battery and ECM, or the engine is not equipped with a real-time clock battery and the vehicle battery power to the ECM is lost.

NOTE:If the Real Time Clock is supplied by the OEM via a CAN BUS and a battery backup is not used, then refer to the OEM wiring diagram. If this is the case, then check INSITE™ electronic service tool, “Advanced ECM Data – Real Time Clock Settings.” If the OEM supplies a Real Time Clock signal, then the address must be set according to the OEM wiring or the fault code will become active.

Refer to Troubleshooting Fault Code t05-319

Last Modified:  08-Jul-2010